Electronic devices, such as two-way portable radios, typically employ electrical circuitry that emits a substantial amount of electromagnetic radiation. The electrical circuitry may also include electronic components that are themselves susceptible to electromagnetic interference. Generally, radiation-emitting components and radiation-sensitive components are shielded with metal shields and the like. However, individual component shielding can be expensive and sometimes impractical. Various approaches are available in the prior art that attempt to provide an overall shield for the circuitry within an electronic device. One common approach is the use of plating or conductive painting on the housing enclosure for the electronic device. The manufacturing process for such an approach can be very expensive and labor intensive. Moreover, the effectiveness of such shielding may be reduced because of holes commonly found in a housing.
A typical portable radio may include a keypad interface that presents the user with access to device controls. In most common designs employing keypads, keyholes are formed within the housing, such that actuation of the keys may cause corresponding actuation of switches located within the housing. These key holes are but one example of a source of potential breach of electrical shielding material disposed on the housing enclosure to protect the circuitry of the electronic device. It is desirable to protect against potential interference for sensitive circuitry in an electronic device in a cost-effective manner. Shielding approaches of the prior art do not sufficiently address this problem.